In the title compound, [Ni(SO4)(C12H8N2)2]·C3H8O2, the NiII atom exhibits a distorted octahedral coordination by four N atoms from two chelating 1,10-phenanthroline ligands and two O atoms from an O,O′-bidentate sulfate group. A twofold rotation axis passes through the Ni and S atoms and the mid-point of the hydroxyl C—C bond of the propane-1,2-diol solvent molecule. The dihedral angle between the two chelating N2C2 groups is 85.61 (8)°. The [NiSO4(C10H8N2)2] and propane-1,2-diol units are held together by a pair of symmetry-related intermolecular O—H⋯O hydrogen bonds involving the uncoordinating O atoms of the sulfate ion. Due to symmetry, the solvent molecule is equally disordered over two positions.